The overriding purpose of this proposal is the improvement of childhood cancer treatment and rehabilitation - both locally and nationally - through institutional participation in Children's Cancer Study Group (CCSG) activities. Inherent in this objective are the following corollary goals, which may be viewed as the means by which the primary purpose is to be achieved: 1. Enlist the participation of patients referred to Vanderbilt and its affiliate, the Oschner Clinic, in CCSG research protocols so as to facilitate the expeditious conduct and timely conclusion of Group-wide clinical studies. 2. By drawing on Vanderbilt's professional resources, to further augument the Group's capabilities for scientific inquiry relative to pediatric oncology, protocol development, and data analysis. 3. Through controlled clinical trials, to assess new modalities of therapy, new combinations and new schedules of therapy, and newly developed pharmacologic agents (Phase II drugs). 4. Participate in Group-wide non-therapeutic investigations which are designed to probe the biology of pediatric tumors; define the relative sensitivity of various diagnostic procedures and imaging techniques; and further characterize the demographic features of selected tumors. 5. Provide students and professionals in training with the background necessary to appreciate and evaluate research regarding the biology and treatment of childhood cancer.